• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.957-966
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• 1998

In this paper an imrpoved Signal-to-Interference ratio(SIR)-based call admission control(CAC) algorithm for DS-CDMA cellular system is proposed and its performance is analyzed. This algorithm uses Residual-Capacity defined asthe additional number of initial calls that a base station can accept such that system-wide outage probability will guaranteed to remain below a certain level. the residual capcity at each cell is calculated according to the reverse-link SIR measured not only at the home cell but also the adjacent cells. Then the adjacent cell interference-coupling coefficient .betha. is used. In this work we propose an improved algorithm that .betha. varies according to the traffic load of the home cell. The influence of traffic condition on system performance, namely blocking probability and outage probability, is then examined via simulation. The performance of the improved algorithm is evaluated both under homogeneous and hot spot traffic loads. The results show that the improved algorithm outperforms conventional algorithms under all load values. Under over-load situation, especially, the improved algorithm gives almost constant outage performance the QoS(quality of service) can be guranted.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.459-467
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• 2013

The purpose of this study was to identify the differences in medical care utilization by regional economic status using the National Hospital Discharge Patients Injury Survey. In order to determine economic status of each region, 234 cities and counties were categorized 5 quintiles according to their financial self-reliance ratio. The main results are as follows. First, low economic region has high age-standardized admission rate and standardized mortality rate. Second, of 16 major diseases, cerebrovascular and heart diseases, lung cancer, and stomach cancer reported greater changes in standardized mortality rate by regional economic status. Third, the rate of admission via emergency room in low economic region is higher than that of high economic region. Lastly, in the major illnesses, lower economic status led to an increase in average length of stay. Therefore, In order to bridge the gap in health inequality across regions, a regional medical policy tailored for each region and characteristics of the economic status should be established.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.84-93
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• 2024

Objective : We aimed to examine trends in critically ill neurology-neurosurgery (NNS) patients who were admitted to the intensive care unit (ICU) in South Korea and identify risk factors for in-hospital mortality after ICU admission in NNS patients. Methods : This nationwide population-based retrospective cohort study enrolled adult NNS adult patients admitted to the ICU from 2010 to 2019 extracted from the National Health Insurance Service in South Korea. The critically ill NNS patients were defined as those whose main admission departments were neurology or neurosurgery at ICU admission. The number of ICU admission, age, and total cost for hospitalization from 2010 to 2019 in critically ill NNS patients were examined as trend information. Moreover, multivariable logistic regression modeling was used to identify risk factors for in-hospital mortality among critically ill NNS patients. Results : We included 845474 ICU admission cases for 679376 critically ill NNS patients in South Korea between January 1, 2010 to December 31, 2019. The total number of ICU admissions among NNS patients was 79522 in 2010, which increased to 91502 in 2019. The mean age rose from 62.8 years (standard deviation [SD], 15.6) in 2010 to 66.6 years (SD, 15.2) in 2019, and the average total cost for hospitalization per each patient consistently increased from 6206.1 USD (SD, 5218.5) in 2010 to 10745.4 USD (SD, 10917.4) in 2019. In-hospital mortality occurred in 75455 patients (8.9%). Risk factors strongly associated with increased in-hospital mortality were the usage of mechanical ventilator (adjusted odds ratio [aOR], 19.83; 95% confidence interval [CI], 19.42-20.26; p<0.001), extracorporeal membrane oxygenation (aOR, 3.49; 95% CI, 2.42-5.02; p<0.001), and continuous renal replacement therapy (aOR, 6.47; 95% CI, 6.02-6.96; p<0.001). In addition, direct admission to ICU from the emergency room (aOR, 1.38; 95% CI, 1.36-1.41; p<0.001) and brain cancer as the main diagnosis (aOR, 1.30; 95% CI, 1.22-1.39; p<0.001) are also potential risk factors for increased in-hospital mortality. Conclusion : In South Korea, the number of ICU admissions increased among critically ill NNS patients from 2010 to 2019. The average age and total costs for hospitalization also increased. Some potential risk factors are found to increase in-hospital mortality among critically ill NNS patients.

• Health Policy and Management
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• v.13 no.3
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• pp.129-147
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• 2003

This study is to grasp a trend of profitability classified by characteristics of hospitals and to analyze related factors. Subjects are 145 hospitals which have gotten the standardization audit by Korean Hospital Association during 1998-200l. Profitability was measured in the aspect of operation profit rate with operating margin to gross revenue as proxy variables. Independent variables were classified by general factors (ownership, number of beds, period of establishment, competition), financial factors (liabilities to total assets, current ratio, fixed ratio, total asset turnover, inventories turnover), and factors related to patient treatment (average length of stay, bed occupancy rate, new outpatient ratio, admission ratio of outpatients, number of patients per specialist, personnel costs per adjusted inpatient, administrative costs per adjusted inpatient). Hierarchical multiple regression analysis model was used in this study. As a result of hierarchical multiple regression analyzation of operating margin to gross revenue, adjustive $R^2$ of general factors was relatively more powerful. The factors had significant effect on operating margin to gross revenue were ownership(+), number of beds(+), competition(+), current ratio(+), fixed ratio(+), total asset turnover(+), personnel costs per adjusted inpatient(-).

• Journal of Korean Neurosurgical Society
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• v.42 no.3
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• pp.173-178
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• 2007

Objective : Hydrocephalus is one of the major complications following spontaneous subarachnoid hemorrhage (SAH). However, the risk factors of the hydrocephalus after SAH are not still well known. This study was focused on verification of the causal relationships between the development of hydrocephalus and SAH. Methods : The patients who developed hydrocephalus after rupture of aneurysms were studied. To obtain prognostic factors regarding to hydrocephalus, several parameters such as age, sex, hypertension, location of aneurysm, existence of intraventricular hemorrhage (IVH) and intracerebral hemorrhage (ICH), Glasgow coma scale (GCS), Hunt-Hess SAH classification & Fisher Grade on admission and the ratio of frontal harn of lateral ventricle diameter to skull inner table diameter at this level (FH/ID) were studied retrospectively. Results : The development of hydrocephalus following SAH is multifactorial. The age, IVH, FH/ID ratio were related to hydrocephalus in analysis. There is a low clinical correlation between sex, hypertension, location of aneurysm, existence of ICH, GCS, Hunt-Hess SAH classification, Fisher Grade on admission and hydrocephalus. Conclusion : Knowledge on risk factors related to the occurrence of hydrocephalus may help guide neurosurgeons in the long-term care of patients who have experienced aneurysmal SAH.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6985-6989
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• 2013

Background: This study aimed to examine out-of-pocket expenditure for cancer treatments of hospitalized patients and to analyze changing patterns over time. Materials and Methods: This study examined data of all cancer patients receiving inpatient care from two tertiary hospitals from January 2003 to December 2010. Medical expenditures per admission were calculated and classified into those covered and uncovered by the Korean National Health Insurance (NHI) and co-payment. Results: The medical expenditure per admission increased slowly from 3,455 thousand Korean won (KRW) to 4,068 thousand KRW. While expenditures covered by the NHI have increased annually, co-payments have generally decreased. The out-of-pocket expenditure ratio, which means the proportion of uncovered expenditure and co-payment among total medical expenditure dropped sharply from 2005 to 2007 and was maintained at a similar level after 2007. Medical expenditures, NHI coverage, and the out-of-pocket expenditure ratio differed across cancer types. Conclusions: It is necessary to continually monitor the expenditure of uncovered services by the NHI, and to provide policies to reduce this economic burden. In addition, an individual approach considering cancer type-specific characteristics and medical utilization should be provided.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1907-1914
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• 1998

This paper proposes the adaptive connection admission cotrol using the variale MRR(measurement reflection ratio) and the distribution of the number of cells arriving during the fixed interval. This distribution is estimated from the measured number of cells arriving at the output buffer during the fixed interval and traffic parameters specified by user. MRR is varied by the difference of estimated distribution and measurement distribution. As MRR is adaptively varied by estimated distribution error of accepted connections, it quickly reduces estimation error. Also, the scheduling scheme is proposed for multiplexed traffic with various traffic characteristics. For each traffic class, this scheme estimates adaptively equivalent bandwidth and schedules according to equivalent bandwidth ratio of each traffic class, so it improves cell loss rate and link utilization.

• Journal of Acupuncture Research
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• v.24 no.3
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• pp.19-28
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• 2007

Objectives : This study was conducted in order to analyze the admission patients of facial nerve paralysis by Sasang constitution. Methods: A clinical study was done on 61 admission patients who were diagnosed and treated as facial nerve paralysis (Bell's palsy) from September, 2005 to May 2006 at the Dept. of Acupuncture and Moxibution, Chung-ju Hospital, college of Daejeon Oriental Medicine. We classified 61 patients according to Sasang constitution by QSCC II, attack side, sex, cause factor, concomitant symptom and Yanagihara' s score at the admission and discharge, and analyzed the improvement of Yanagihara's score between Sasang constitution groups. Results: 1. By sex, the ratio of Taeumin was higher than that of Soyangin in female. 2. By attack side, there is no significant difference between constitution groups In concomitant symptoms and cause factors. 3. By improvement of Yanagihara's scores between admission and discharge, the improvement score in Soyangin was a little bit higher than that in Soeumin, but there is no significant difference. Conclusion : The results suggest that there is no significant difference in all aspects except sex in Sasang constitution. But it is considered that we need to keep on studying afterwards because we had limits in getting enough patients.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.1049-1068
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• 2011

In this paper a simple and effective call admission control (CAC) scheme is proposed for the emerging interleave-division multiple-access (IDMA) systems, supporting a variety of traffic types and offering different quality of service (QoS) requirements and priority levels. The proposed scheme is signal-to-interference-plus-noise ratio (SINR) evolution based CAC (SE-CAC). The key idea behind the scheme is to take advantage of the SINR evolution technique in the process of making admission decisions, which is developed from the effective chip-by-chip (CBC) multi-user detection (MUD) process in IDMA systems. By virtue of this semi-analytical technique, the MUD efficiency can be estimated accurately. Additionally, the computational complexity can be considerably reduced. These features make the scheme highly suitable for IDMA systems, which can combat intra-cell interference efficiently with simple CBC MUD. Analysis and simulation results show that compared to the traditional CAC scheme considering MUD efficiency as a constant, the proposed SE-CAC scheme can guarantee high power efficiency and throughput for multimedia traffic even in heavy load conditions, illustrating the high efficiency of CBC MUD. Furthermore, based on the SINR evolution, the SE-CAC can make accurate estimation of available resource considering the effect of MUD, leading to low outage probability as well as low blocking and dropping probability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.581-593
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• 2002

In this paper, we proposed an Adaptive RIO scheme to solve the problem of RIO scheme that occurs when admission control is performed for QoS guarantee of Assured Service in Differentiated Services. To prevent an early random drop of the admitted In-profile packet, proposed Adaptive RIO scheme updates parameters of RIO scheme every time interval according to the estimated numbers of maximum packet arrivals of In-profile traffic and total traffic during the next time interval. The numbers of maximum packet arrivals during the next time interval are estimated based on the buffer size determined by the network topology and the ratio of bandwidth allocated to each subclass. We found from simulation results that, compared with RIO scheme, proposed Adaptive RIO scheme can improve performance of the throughput for In-profile traffic when admission control is performed or congestion occurs.