• 한국병원경영학회지
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• 제9권2호
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• pp.102-127
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• 2004

The objective of this study is to analyze a current trend of and relating factors on profitability of the Korean Public Corporation Medical Centers(KPCMCs, hereinafter, hospitals) in Korea. There are 34 hospitals in Korea as of 2004. Among these hospitals some are red ink hospitals, others are black inks in terms of profitability. Data were collected by Korea Health Industry Development Institute(KHIDI) Statistics for Hospital Management 2000-2002 and Ministry of Health and Welfare(MOHW) financial data of public hospitals which was planned to coordinate public health care services roadmap in the long run. The samples are 32 hospitals. Profitability was measured in the aspect of profit rate with normal profit to total assets, and normal profit to gross revenues as dependent variables in respective. Independent variables were classified by general factors, i.e., location, intern/resident training, period of opening, number of beds, and managerial factors(current ratio, fixed ratio, liability to total assets, total assets turnover, personnel costs, materials cost, administrative cost), and finally factors related to patient treatment(average length of stay, bed occupancy rate, admission ratio of outpatients). The methods of analysis are correlation and multiple regression analysis. This study shows firstly, a lot of hospitals are optimal current ratio. Hospitals in upper 100% current ratio are 81.2%. And the personnel cost in total costs are high. Secondly, the trend of normal profit to gross revenues of hospitals are deteriorating gradually. And lastly, as a result of multiple regression analysis, the factors had on significant effect on normal profit to total assets are fixed ratio(+), liability to total assets(-), bed occupancy rate(+), admissions of outpatients(+), etc. And the factors had on significant effect on normal profit to gross revenues are current ration(+), fixed ratio(+), personnel cost(-), administrative expenses(-), admissions of outpatients(+), etc. In conclusion, to improve the profitability of hospitals, the efforts to reduce personnel cost and average length of stay might be needed. And also beds utilization rate need to be increased.

• 전기학회논문지
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• 제59권11호
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• pp.2058-2065
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• 2010

This paper presents the sensor location and step estimation algorithm for personal navigation system (PNS). PNS has the disadvantage in that the position of the sensor must be fixed on a human body. Three-axis acceleration sensor is used to solve the disadvantage and to consider the real situation. We simplify the measurement data by using the band pass filter, witch It has the advantage in the detection of characteristic point. Through the detected characteristic points, it is possible to setup the parameter for the pattern detection. Depending on the sensor location, the parameters have the different type of noise covariance. Particularly, when the position of the sensor is changed, the impulse noise shows up. Considering the noise, we apply the recursive least square algorithm using the variable forgetting factors, which can classify the sensor location based on the estimated parameters. We performed the experiment for the verification of the proposed algorithm in the various environments. Through the experimental results, the effectiveness of the proposed method is verified.

• 한국멀티미디어학회논문지
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• 제11권2호
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• pp.182-196
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• 2008

센서 네트워크를 이용한 위치 추정은 많은 연구가 되어왔다. 실내 혹은 실외에서 위치추정 방식의 차이를 고려한 방법이 연구되고 있다. 실외의 위치 추정에서 RSSI(Received Signal Strength Indication) 값을 통하여 단일 시간 동안 일정하게 한 분포를 가지기 때문에 추론이 가능하지만, 실내는 다중경로와 간섭이 실외보다 높고, 그 밖에 다른 변수로 인해 추론하기가 어렵다. 논문에서는 이동평균과 K-means 알고리즘을 통해 다중경로와 간섭으로 변화된 RSSI 정보를 보정하고, 단일 시간 동안 수신된 수신신호의 집단에서 신뢰성을 가진 RSSI의 값에 대한 추론을 제안한다. 또한 위치추정에서 보정노드를 이용하여 네트워크에 속한 고정 노드에 가중치를 두는 방법을 제안하고, 네트워크 재설정을 통해 기존의 방식을 시스템 상에서 새롭게 구현하여 위치인지에 대한 효율성을 비교 평가한다.

• 산업진흥연구
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• 제6권3호
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• pp.19-24
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• 2021

과학적 품질경영을 하기 위해서는 측정시스템에 문제가 없어야 한다. 이에 본 논문에서는 측정과정 중 측정결과에 영향을 미칠 수 있는 요인들이 무엇인지 확인하여 측정결과가 위치와 변동 면에서 문제점이 발생할 때 이를 야기하는 요인을 나열하고자 한다. 측정시스템의 변동은 크게 위치와 산포의 두 가지 속성으로 묘사되는데, 위치와 관련된 속성으로는 정확성, 안정성, 직선성이 있고, 산포와 관련된 속성으로는 재현성과 반복성이 있다. 측정시스템분석에서는 산포와 관련된 요소를 분석하는 것이 R&R분석인데, 여기서 반복성과 재현성의 크기는 여러 차례의 측정치간 차이인 범위와 측정자간 차이인 범위로 나타내며, 이들 범위를 이용한 99%의 산포로 그 크기를 파악한다. 측정시스템분석은 R&R분석이외에 실험계획을 활용하여 측정치의 변동을 유발하는 요인의 변동의 크기를 추정할 수 있다. 이때 변동을 야기하는 요인인 작업자와 제품이 랜덤요인인지 또는 고정요인인지 점검하여 그에 맞게 각 요인의 변동의 크기를 구해야 적절한 분석이 이루어진다.

• Wind and Structures
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• 제20권4호
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• pp.489-508
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• 2015

In this paper, a novel methodology is proposed to obtain optimum location of outriggers. The method utilizes genetic algorithm (GA) for shape and size optimization of outrigger-braced tall structures. In spite of previous studies (simplified methods), current study is based on exact modeling of the structure in a computer program developed on Matlab in conjunction with OpenSees. In addition to that, exact wind loading distribution is calculated in accordance with ASCE 7-10. This is novel since in previous studies wind loading distributions were assumed to be uniform or triangular. Also, a new penalty coefficient is proposed which is suitable for optimization of tall buildings. Newly proposed penalty coefficient improves the performance of GA and results in a faster convergence. Optimum location and number of outriggers is investigated. Also, contribution of factors like central core and outrigger rigidity is assessed by analyzing several design examples. According to the results of analysis, exact wind load distribution and modeling of all structural elements, yields optimum designs which are in contrast of simplified methods results. For taller frames significant increase of wind pressure changes the optimum location of outriggers obtained by simplified methods. Ratio of optimum location to the height of the structure for minimizing weight and satisfying serviceability constraints is not a fixed value. Ratio highly depends on height of the structure, core and outriggers stiffness and lateral wind loading distribution.

• 보건행정학회지
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• 제12권4호
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• pp.1-17
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• 2002

This study was attempted to identify the liquidity trends and determinants of private hospitals in Korea different. Data used in this study were collected from 98 hospitals with complete general data of present conditions as well as financial statements(balance sheets, income statements). They were chosen from hospitals that passed the standardization audit undertaken by the Korean Hospital Association from 1996 to 2000 for the purpose of accrediting training hospitals. The dependent variables in this study were used current ration and quick ratio as a proxy indicator for liquidity. The independent variables were ownership type, hospital type, location, bed size, period of establishment, short-term liabilities to total assets, long-term liabilities to total assets, borrowings to total assets, fixed asset ration, net profit to total assets, operating margin to gross revenue, growth rate of net worth to total assets, total asset turnover, and business risk(volatility of profit). The major findings of this study were as follows. Trends of liquidity(current ratio, quick ratio) had been continuously decreased. Especially, There were very distinct decreasing trends of personal hospitals and less than 300beds, which weakened liquidity. The factors had significant effect on current ratio were short-term debt to total assets(-), fixed asset ratio(-), business risk(+). High short-term debt to total assets, high fixed asset ratio and high business risk significantly decreased in liquidity. The factors that significantly affected on quick ratio were short-term debt to total assets(-), borrowings to total assets(+), fixed asset ratio(-), business risk(+).

• Computers and Concrete
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• 제33권3호
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• pp.251-264
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• 2024

The present study pertains to the effects of variations in the location and size of drilled web openings on the behavior of fixed-fixed reinforced concrete (RC) beams. For this purpose, a reference bending beam with a transverse opening in each half span was tested to failure. Later, the same beam was modeled and analyzed with the help of finite element software using ABAQUS. Upon achieving close agreement between the experimental and numerical results, the location and size of the web opening were altered to uncover the effects of these factors on the shear strength and load-deflection behavior of RC beams. The experimental failure mode of the tested beam and the numerical results were also verified by theoretical calculations. In numerical analysis, when compared to the reference (D0) specimen, if the distance of the opening center from the support is 0 or h or 2h, reduction in load-bearing capacity of 1.5%-22.8% or 2.0%-11.3% or is 4.1%-40.7%. In other words, both the numerical analyses and theoretical calculations indicated that the beam behavior shifted from shear-controlled to flexure-controlled as the openings approached the supports. Furthermore, the deformation capacities, energy absorption values, and the ductilities of the beams with different opening diameters also increased with the decreasing distance of the opening from supports. Web compression failure was shown to be the predominant mode of failure of beams with large diameters due to the lack of sufficient material in the diagonal compression strut of the beam. The present study indicated that transverse openings with diameters, not exceeding about 1/3 of the entire beam depth, do not cause the premature shear failure of RC beams. Finally, shear damage should be prevented by placing special reinforcements in the areas where such gaps are opened.

• 대한기계학회논문집
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• 제16권7호
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• pp.1255-1265
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• 1992

본 연구에서는 단열 및 온도가 영으로 고정된 경계조건을 갖는 대칭 입술형과 대칭 익형 강체함유 물상의 접합경계면 균열에 대한 Hilbert 문제로부터 복소 포텐셜 함수와 커스프 균열선단 그리고 접합경계면 균열선단에서 TSIF를 구하고자 한다.

• 한국병원경영학회지
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• 제7권3호
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• pp.25-43
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• 2002

This study focuses on the factors that make the financing decision of private hospitals in Korea. Data used in this study were collected from 98 hospitals with complete general data of current status as well as financial statements. They were chosen from the 138 hospitals that passed the accreditation process by the Korean Hospital Association from 1996 to 2000 for the purpose of accrediting training hospitals. The dependent variables in this study consist of total liabilities to total assets, borrowings to total assets. The independent variables are ownership, hospital type, teaching status, location, bed size, period of establishment, asset structure, profitability, growth, tax shields, volatility of profit, competition(market concentration), and other factors. The major findings of this study are as follows. The factors found to have significant effect on liabilities to total assets are teaching status(-), asset structure(-), profitability(-), tax shields(+), and business risk(-). University hospitals have less liabilities than the non-university hospitals. It was also confirmed that high profitability, high fixed asset, high volatility of profit and low tax shields results in decrease in liabilities. The factors that significantly affect on borrowings to total assets are teaching status(-), period of establishment(-), volatility of profit(-) and competition(+).

• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.85-90
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• 2021

The purpose of this study is to consider usefulness of using AEC mode and importance of patient center location in L-spine lateral radiography by comparing dose and image quality according to the change of patient center location with using AEC mode or not. In this study, guide wire is attached to the human body phantom's lumbar spine and the lead ruler is attached to the bottom of the wall detector to find out center location in detector. ESD, mAs, and EI were selected as dose factors, and image quality was compared through SNR. With the lumbar spine located center of the detector, dose factors and image quality were compared according to using AEC mode or not. Afterwards, phantom moved 4 cm and 8 cm back and forth and compared dose factors and image quality. The exposure parameters were 85 kVp, 320 mA, x-ray field size 10×17 inch, and the distance between the center X-ray and the detector was fixed at 100 cm. The center X-ray was perpendicular to the fourth lumbar spine and the only bottom AEC chamber was used. All data were analyzed by independent t-test and ANOVA. As a result of this study, with AEC when the center is matched, ESD was 1.31±0.01 mGy, without AEC was 2.12±0.01 mGy. SNR was shown to be 22.81±1.83, and 23.44±1.87 respectively. When the phantom's center moves 4 cm, 8 cm forward, and 4 cm, 8 cm backward, ESD were 1.09±0.004 mGy, 0.32±0.003 mGy, 1.19±0.017 mGy, 1.11±0.006 mGy respectively, SNR were 18.29±0.60 dB, 11.11±0.22 dB, 18.98±0.80 dB, 17.71±0.82 dB. Using AEC in L-spine lateral radiography reduced ESD by 38%, EI by 35%, and mAs by 38%, without any difference in SNR(p<0.05). When the phantom's center moves 4 cm, 8 cm forward, and 4 cm, 8 cm backward, ESD was decreasing each 16%, 75%, 9%, 15%, EI was decreasing each 14%, 77%, 15%, 20%, mAs was decreasing each 15% 75% 9%, 15%. SNR was decreasing each 19%, 51%, 17%, 22%.