• 대한교통학회지
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• 제21권1호
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• pp.91-102
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• 2003

본 연구는 $\circled1$Cellular Automata(이하 CA)모형을 기반으로 대규모 네트워크에 적용 가능한 보다 현실적인 CA차량모형 구축. $\circled2$구축된 CA차량모형을 이용한 차량 모의실험기의 개발과 개발된 차량 모의실험기를 이용한 단기링크통행시간 예측으로 구성된다. 구축된 CA차량추종모형은 기존의 CA차량추종모형 보다 현실적으로 감속을 통한 정지과정을 설명하면서 거시적 지표인 교통량-밀도-속도관계를 설명하였다. 또한 링크의 유출교통량(Outflow)을 제어하기 위한 차량의 링크전이모형은 기존의 차량 링크전이모형에 비하여 보다 안정된 대기차량을 형성하였다. 단기링크통행시간 예측을 위한 차량모의실험기는 대규모 가로망에 적용이 가능하도록 차량묶음(Packet, 이하차량묶음)방식과 링크기반 모의실험방식으로 컴퓨터의 연산 수행속도 및 메모리를 효율적으로 처리할 수 있었으며, 기존의 시계열자료 예측기법에서 고려할 수 없었던 차량의 행태 및 링크 상에서 발생하는 이동류 과포화, 뒷막힘현상 등의 메커니즘을 고려함으로서 기존 시계열자료 예측기법에 비하여 우수한 예측력을 보였다.

• 중환자간호학회지
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• 제3권1호
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• pp.41-51
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• 2010

Purpose: The purpose of this study was to identify the effects of family visits upon the stress response of patients and their families, Methods: This study was the interrupted time series design, The subjects consisted of 197 patients and 197 family members in the cardiac intensive care unit of S Hospital in Bucheon. Physiological stress responses such as blood pressure, heart rates, respiration rates, and oxygen saturation were measured using HP monitors. VAS was used to measure the emotional stress. Collected data was analyzed using repeated measure ANOVA, t-test by SPSS 17.0 statistical program. Results: The family visits did not change patients' blood pressure, pulse rate, respiration rate and oxygen saturation, However the anxiety level of patients and their family members were decreased significantly during family visits. Furthermore, 30-minute family visit reduced more effectively patient's anxiety than 15-minute family visit. Conclusion: Family visits need to be used as a means of nursing intervention to ease the emotional stress of patients and their families. In addition, increasing of visiting time should be considered.

• 한국병원경영학회지
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• 제27권1호
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• pp.20-30
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• 2022

Purposes: This study purposed to evaluate the effect of a value incentive program(VIP) on the in-hospital mortality of acute stroke. Methodology: Study period was from January 2010 to December 2018. This study included 63 hospitals for acute hemorrhagic stroke that the mortality rate per month was more than one during study period. Independent variables were time variables and hospital characteristics such as hospital type, district and bed number. Interrupted time series analysis was applied to analyze the data. Findings: In case of general hospitals, the in-hospital mortality rate per month for acute hemorrhagic stroke tends to be increased by 0.03% in overall study periods but decreased by 0.32% after the implementation of the policy. On the other hand, tertiary hospital changes are not statistically meaningful. Conclusion: This study provides evidences how the VIP was effective in improving quality of acute hemorrhagic stroke care. General hospitals showed higher policy effect compare to that of tertiary hospitals.

• 한국진공학회지
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• 제22권2호
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• pp.92-97
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• 2013

Migration-enhanced epitaxy 성장한 InAs/GaAs 양자점(quantum dots)의 광학적 특성을 PL (photoluminescence)과 Time-resolved PL 이용하여 분석하였다. InAs 양자점은 In을 9.3초 공급하고 5초 차단한 후 As을 3초, 4초, 6초, 또는 9초 공급하고 5초 차단하는 과정을 3회 반복하여 성장하였다. As을 3초 공급한 시료의 PL 피크는 1,140 nm에서 나타나고, PL 세기는 다른 세 시료에 비해 매우 약하게 나타났다. As 공급시간을 3초에서 증가하였을 때 모든 PL 피크는 1,118 nm로 청색이동하여 나타났으며, PL 세기는 증가하였다. As을 6초 공급한 시료의 PL 세기가 가장 강하게 나타나고, 반치폭(full width at half maximum)도 가장 좁게 나타났다. 이러한 결과는 양자점의 밀도와 균일도(크기변화)로 설명된다. 또한 발광파장에 따른 PL 소멸시간은 PL 피크 근처에서 가장 길게 나타났다.

• 중환자간호학회지
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• 제5권2호
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• pp.28-36
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• 2012

Purpose: The purpose of this study was to examine the effects of the systematic breathing exercise program on recovery of patients with pneumothorax. Methods: An nonequivalent interrupted time-series control group posttest design was used. Participants were 40 inpatients (Experimental Group; 20, Control Group; 20) at the one University Hospital in U city. The systematic breathing exercise program including education on deep breathing exercise using incentive spirometry, Range of motion (ROM) exercise in shoulder joint, walking exercise and feedback were provided to the experimental group, while the control group carried out deep breathing exercise using incentive spirometry. The duration of chest tube insertion, duration of hospitalization, and frequency of analgesics use were measured. The data were analysed by a SPSS/WIN program. Results: The duration of chest tube insertion and duration of hospitalization in the experimental group were significantly shorter than the control group. However, there is no difference of the frequency of analgesics use between the experimental group and control group. Conclusion: The result showed that the systematic breathing exercise program was effective to improve recovery of patients with pneumothorax. This program can be applied in hospitals for patients with pneumothorax as one of the nursing intervention modalities.

• Journal of Preventive Medicine and Public Health
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• 제43권6호
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• pp.496-504
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• 2010

Objectives: The purpose of this study was to analyze the effect of outpatient cost-sharing on health care utilization by the elderly. Methods: The data in this analysis was the health insurance claims data between July 1999 and December 2008 (114 months). The study group was divided into two age groups, namely 60-64 years old and 65-69 years old. This study evaluated the impact of policy change on office visits, the office visits per person, and the percentage of the copayment-paid visits in total visits. Interrupted time series and segmented regression model were used for statistical analysis. Results: The results showed that outpatient cost-sharing decreased office visits, but it also decreased the percentage of copayment-paid visits, implying that the intensity of care increased. There was little difference in the results between the two age groups. But after the introduction of the coinsurance system for those patients under age 65, office visits and the percentage of copayment-paid visits decreased, and the 60-64 years old group had a larger decrease than the 65-69 years old group. Conclusions: This study evaluated the effects of outpatient cost-sharing on health care utilization by the aged. Cost sharing of the elderly had little effect on controlling health care utilization.

• 한국의료질향상학회지
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• 제17권1호
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• pp.69-78
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• 2011

Objectives : The purpose of this study was to determine whether the published AMI report card could reduce in-patient mortality, 7-day after discharge mortality, and length of stay (LOS). Methods : Interrupted time-series intervention analysis was used to evaluate the impact of the report card for AMI care quality in November 2005 in terms of risk-adjusted in-patient mortality, risk-adjusted 7-day after discharge mortality, and DRGs case-mix LOS using the claim data of Health Insurance Review and Assessment Service. Results : Public disclosure of AMI care quality decreased risk-adjusted in-patient mortality and DRGs case-mix LOS by 0.00050% per month and 0.042 days per month respectively, however there was no effect on risk-adjusted 7-day after discharge mortality. Patterns of effect of public disclosure on AMI outcomes were a fluctuating pattern on risk-adjusted mortalities and a pulse impact for 1 month on DRGs case-mix LOS. Conclusions : We found the public disclosure of AMI care quality had decreasing effects on risk-adjusted in-patient mortality and DRGs case-mix LOS, but the size of the effect was marginal.

• Clinical and Experimental Pediatrics
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• 제64권3호
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• pp.123-129
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• 2021

Background: The use of indwelling central venous access devices (CVADs) in children can result in complications such as infection, occlusion, and dislodgement. Purpose: To evaluate whether reinforcing CVAD care bundles by using a regular direct feedback system could reduce such complications in children. Methods: The intervention in this retrospective interrupted time-series study was initiated in January 2019. The study was divided into the preintervention (October-December 2018), 3-month postintervention (January-March 2019), and 6-month postintervention (April-June 2019) phases. Risk difference and Poisson regression analyses were used to illustrate the effectiveness of the intervention. Results: The hospital-wide central line-related bloodstream infection rate decreased from 10.0/1,000 catheter-days to 4.5/1,000 catheter-days at 3-month postintervention (P=0.39) and to 1.4/1,000 catheter-days at 6-month postintervention (P=0.047). The central line occlusion rate significantly decreased from 30% to 12.8% (P=0.04) and 8.3% (P=0.002) at 3 and 6 months, respectively. Approximately 7% of CVADs became dislodged during the preintervention phase versus 8.5% (P=0.364) and 3.3% (P=0.378) at 3 and 6 months, respectively. Conclusion: Reinforcing CVAD care bundles with direct feedback could significantly decrease CVAD-associated complications in terms of infection at 6-month postintervention, and occlusion at 3- and 6-month postintervention. Thus, reinforcement and regular direct feedback might improve care quality in children with CVADs.

• 대한교통학회지
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• 제18권4호
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• pp.75-85
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• 2000

본 연구에서는 도시부도로 신호교차로의 대기행렬을 단기(one cycle ahead)예측함에 있어 단일검지체계에 기반을 둔 한 지점의 시계열적 패턴을 갖는 검지자료(detection data)를 학습자료로 구성할 경우와 통합차량검지체계하에 기반을 둔 시공간적 상관관계를 갖는 검지자료를 학습자료로 이용할 경우를 가정하여 이에 대한 인공신경망의 학습능력과 예측능력을 비교하였다. 연구결과는 도시부도로 신호교차로상에서 차량군(platoon)의 이동에 따라 발생되는 시공간적인 상관관계를 갖는 교통류변수 $\ulcorner$상류유입교통량(k-1)->통행시간(k-1)->대기행렬(k)->유출교통량(k)->대기행렬(k+1)$\lrcorner$를 인공신경망의 학습자료로 구성할 경우, 교통류 패턴의 학습능력이 뛰어난 것으로 밝혀졌다.

• 한국의료질향상학회지
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• 제24권2호
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• pp.62-75
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• 2018

Purpose: The objective of this study was to publicly report the hospital-level surgical volume for 7 types of surgery including gastrectomy. Also, to investigate the changes in patient behaviors after the public reporting among patients with gastrectomy. Methods: This study used data from the National Health Insurance Service Cohort. The data comprised of 2,214 patients who were diagnosed with gastric cancer and underwent gastrectomy during 2004-2012. An interrupted time series analysis was performed to investigate the association between patients' choice and public reporting. Results: 79.27% of the patients visited a hospital with high surgical volume. The time trend after introduction of public reporting was positively associated with visiting a high volume hospital (per 1 month, RR: 1.004, p=0.0329). However, after adjusting the health policies by reducing copayment, public reporting on surgical volume was not associated with visiting a high volume hospital. Sub-group analyses had also similar results. Conclusion: Patients were more affected by policies on economic support than on public reporting, and the changes in treatment options may have been affected by the increasing preference for large size hospitals. Thus, public reporting did not significantly improve the options available for patients and their decision making on health care utilization.